1. Field of Invention
The present invention relates generally to robotic systems and, more particularly, to surgical systems for orthopedic joint replacement surgery.
2. Description of Related Art
Robotic systems are often used in applications that require a high degree of accuracy and/or precision, such as surgical procedures or other complex tasks. Such systems may include various types of robots, such as autonomous, teleoperated, and interactive.
Interactive robotic systems are preferred for some types of surgery, such as joint replacement surgery, because they enable a surgeon to maintain direct, hands-on control of the surgical procedure while still achieving a high degree of accuracy and/or precision. For example, in knee replacement surgery, a surgeon can use an interactive, haptically guided robotic arm in a passive manner to sculpt bone to receive a joint implant, such as a knee implant. To sculpt bone, the surgeon manually grasps and manipulates the robotic arm to move a cutting tool (such as a burr) that is coupled to the robotic arm to cut a pocket in the bone. As long as the surgeon maintains a tip of the burr within a predefined virtual cutting boundary defined, for example, by a haptic object, the robotic arm moves freely with low friction and low inertia such that the surgeon perceives the robotic arm as essentially weightless and can move the robotic arm as desired. If the surgeon attempts to move the tip of the burr to cut outside the virtual cutting boundary, however, the robotic arm provides haptic (or force) feedback that prevents or inhibits the surgeon from moving the tip of the burr beyond the virtual cutting boundary. In this manner, the robotic arm enables highly accurate, repeatable bone cuts. When the surgeon manually implants a knee implant (such as a patellofemoral component) on a corresponding bone cut the implant will generally be accurately aligned due to the configuration of and interface between the cut bone and the knee implant.
The above-described interactive robotic system, though useful for knee replacement surgery, it is not optimally suited for types of surgery, such as hip replacement surgery, that require the use of multiple surgical tools having different functions (e.g., reaming, impacting), different configurations (e.g., straight, offset), and different weights. A system designed to accommodate a variety of tools may be prohibitively complex and require multiple end effectors, and removing and attaching different types of tools to the robotic arm during a surgical procedure could increase the time to perform the procedure. Additionally, in hip replacement surgery, in addition to maintaining an appropriate cutting boundary, angular orientation of surgical tools and implants is important. For example, in conventional hip replacement surgery, the surgeon uses a hemispherical reamer to resurface a patient's acetabulum, which is a cup-shaped socket in the pelvis. Then, a corresponding cup-shaped implant (an acetabular cup), is attached to a distal end of an impactor tool. The surgeon implants the acetabular cup into the reamed socket by repeatedly striking a proximal end of the impactor tool with a mallet. Angular orientation of both the reamed socket and the implanted acetabular cup is important because incorrect individual and/or relative orientation can result in misalignment of the acetabular cup to the appropriate version and inclination angles of the patient's acetabular anatomy. Misalignment can lead to post-operative problems, including joint dislocation, impingement of the femur on the acetabular cup at the extreme ranges of motion of the femur, and accelerated wear of the acetabular cup due to improper loading of the femoral head-to-acetabular cup interface. Alignment is also important to maintain correct leg length and medial/lateral offset. Finally, impacting the acetabular cup into the reamed socket generates high impact forces that could potentially damage a robotic arm designed for highly accurate and/or precise operation.
In view of the foregoing, a need exists for an improved robotic surgical system and components thereof.